1. Technical Field
The present invention relates to a printing apparatus, a printing system, and a printing method.
2. Related Art
An ink jet printer is provided with a printing head that includes a plurality of nozzles for discharging ink. In such a printing head, nozzles may be clogged due to causes such as when the viscosity of ink increases, when air bubbles are mixed therein, and when grime or paper dust is attached thereto. Clogging (abnormal discharging) of a nozzle causes a missing dot (a type of image degradation) because ink that is to be discharged to a print substrate is not discharged.
There is known a printing control device (refer to JP-A-2001-150685) that supplies a control signal for controlling the movement of a nozzle array to a printing unit which prints an image by forming dots with the nozzle array while moving the nozzle array in a main-scanning direction and a sub-scanning direction with respect to a printing medium. The printing control device is provided with a failed block recognizer, a complementing operation storage device, and a control signal supplier. The failed block recognizer regards the nozzle array as a collection of continuous three or more blocks, each of which includes the same number of nozzles, and recognizes a failed block including a failed nozzle when a nozzle that fails to form a dot occurs in the nozzle array. The complementing operation storage device associates the position of the failed block in the nozzle array with a complementing operation and stores the complementing operation in advance, the complementing operation being intended for complementing the failed block with another block by moving the nozzle array in the sub-scanning direction. The control signal supplier supplies the control signal for printing an image to the printing unit while performing the complementing operation that corresponds to the position of the failed block when the failed block is recognized.
It is necessary to resolve a missing dot caused by such a nozzle having abnormal discharge function as described above. In addition, there is room for improving image quality at the time of complementation when a missing dot is complemented by ink discharged from another nozzle.